Rinse and soak the Urad Dal in plenty of Water for 4–6 hours or overnight until the dal is swollen and soft.
Drain the dal and grind it in a blender or wet grinder with very little water to a smooth, thick batter—scrape down sides and grind in short bursts so the batter stays airy.
Transfer the batter to a bowl and beat it vigorously with a spoon or by hand for 5–10 minutes until it becomes light and fluffy and holds soft peaks.
Finely chop the Green Chilies and Ginger. Add them to the batter along with coarsely crushed Cumin Seeds, freshly crushed Black Pepper, chopped Curry Leaves, a pinch of Asafoetida, and Salt; fold gently to distribute evenly.
Heat enough Oil in a deep frying pan over medium heat—test by dropping a little batter in: it should sizzle and rise slowly when ready.
Wet your hands, take a golf-ball sized portion of batter, flatten it into a disc on your palm, and make a hole in the center with your thumb to form the traditional doughnut shape. Repeat with remaining batter.
Carefully slide a few vadas into the hot oil, keeping the heat at medium so they cook through without burning; fry until golden brown and crisp on both sides, turning once (about 3–4 minutes per side).
Remove the vadas with a slotted spoon and drain on paper towels. Serve hot with coconut chutney and sambar, or enjoy them plain as a crunchy, savory snack.
